Gerbil

[ A Young Gerbil [1] Gerbil,

an open source chess engine under the GNU General Public License [2], written by Bruce Moreland, written for educational purposes. It has a decent search ( null move pruning, hash tables) but a rudimentary evaluation [3].

Features

Bruce on Gerbil [4]:

It is using 0x88 move generation. The function is something under 200 lines long, which seems big, but there are a lot of comments and there’s some repeated code.
It is using vanilla windowed alpha-beta with no PVS or anything like that, and I plan to keep it this way, since that is clear and performs acceptably.
It has a check extension. I think that is enough for now. I may try to do some pruning in the quiescence search, which uses MVV/LVA. I don’t plan to write a static exchange evaluator.
This is already a more or less fully functional winboard engine, an effort that consumed a whole bunch of time, not that Mann’s standard is hard to write to. I just had to spend a lot of time messing with threads.